| 1 | /* Functions that provide the mechanism to parse a syscall XML file |
| 2 | and get its values. |
| 3 | |
| 4 | Copyright (C) 2009-2015 Free Software Foundation, Inc. |
| 5 | |
| 6 | This file is part of GDB. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 3 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "gdbtypes.h" |
| 23 | #include "xml-support.h" |
| 24 | #include "xml-syscall.h" |
| 25 | #include "gdbarch.h" |
| 26 | |
| 27 | /* For the struct syscall definition. */ |
| 28 | #include "target.h" |
| 29 | |
| 30 | #include "filenames.h" |
| 31 | |
| 32 | #ifndef HAVE_LIBEXPAT |
| 33 | |
| 34 | /* Dummy functions to indicate that there's no support for fetching |
| 35 | syscalls information. */ |
| 36 | |
| 37 | static void |
| 38 | syscall_warn_user (void) |
| 39 | { |
| 40 | static int have_warned = 0; |
| 41 | if (!have_warned) |
| 42 | { |
| 43 | have_warned = 1; |
| 44 | warning (_("Can not parse XML syscalls information; XML support was " |
| 45 | "disabled at compile time.")); |
| 46 | } |
| 47 | } |
| 48 | |
| 49 | void |
| 50 | set_xml_syscall_file_name (struct gdbarch *gdbarch, const char *name) |
| 51 | { |
| 52 | return; |
| 53 | } |
| 54 | |
| 55 | void |
| 56 | get_syscall_by_number (struct gdbarch *gdbarch, |
| 57 | int syscall_number, struct syscall *s) |
| 58 | { |
| 59 | syscall_warn_user (); |
| 60 | s->number = syscall_number; |
| 61 | s->name = NULL; |
| 62 | } |
| 63 | |
| 64 | void |
| 65 | get_syscall_by_name (struct gdbarch *gdbarch, const char *syscall_name, |
| 66 | struct syscall *s) |
| 67 | { |
| 68 | syscall_warn_user (); |
| 69 | s->number = UNKNOWN_SYSCALL; |
| 70 | s->name = syscall_name; |
| 71 | } |
| 72 | |
| 73 | const char ** |
| 74 | get_syscall_names (struct gdbarch *gdbarch) |
| 75 | { |
| 76 | syscall_warn_user (); |
| 77 | return NULL; |
| 78 | } |
| 79 | |
| 80 | #else /* ! HAVE_LIBEXPAT */ |
| 81 | |
| 82 | /* Structure which describes a syscall. */ |
| 83 | typedef struct syscall_desc |
| 84 | { |
| 85 | /* The syscall number. */ |
| 86 | |
| 87 | int number; |
| 88 | |
| 89 | /* The syscall name. */ |
| 90 | |
| 91 | char *name; |
| 92 | } *syscall_desc_p; |
| 93 | DEF_VEC_P(syscall_desc_p); |
| 94 | |
| 95 | /* Structure that represents syscalls information. */ |
| 96 | struct syscalls_info |
| 97 | { |
| 98 | /* The syscalls. */ |
| 99 | |
| 100 | VEC(syscall_desc_p) *syscalls; |
| 101 | |
| 102 | /* Variable that will hold the last known data-directory. This is |
| 103 | useful to know whether we should re-read the XML info for the |
| 104 | target. */ |
| 105 | |
| 106 | char *my_gdb_datadir; |
| 107 | }; |
| 108 | |
| 109 | /* Callback data for syscall information parsing. */ |
| 110 | struct syscall_parsing_data |
| 111 | { |
| 112 | /* The syscalls_info we are building. */ |
| 113 | |
| 114 | struct syscalls_info *syscalls_info; |
| 115 | }; |
| 116 | |
| 117 | static struct syscalls_info * |
| 118 | allocate_syscalls_info (void) |
| 119 | { |
| 120 | return XCNEW (struct syscalls_info); |
| 121 | } |
| 122 | |
| 123 | static void |
| 124 | syscalls_info_free_syscalls_desc (struct syscall_desc *sd) |
| 125 | { |
| 126 | xfree (sd->name); |
| 127 | } |
| 128 | |
| 129 | static void |
| 130 | free_syscalls_info (void *arg) |
| 131 | { |
| 132 | struct syscalls_info *syscalls_info = arg; |
| 133 | struct syscall_desc *sysdesc; |
| 134 | int i; |
| 135 | |
| 136 | xfree (syscalls_info->my_gdb_datadir); |
| 137 | |
| 138 | if (syscalls_info->syscalls != NULL) |
| 139 | { |
| 140 | for (i = 0; |
| 141 | VEC_iterate (syscall_desc_p, syscalls_info->syscalls, i, sysdesc); |
| 142 | i++) |
| 143 | syscalls_info_free_syscalls_desc (sysdesc); |
| 144 | VEC_free (syscall_desc_p, syscalls_info->syscalls); |
| 145 | } |
| 146 | |
| 147 | xfree (syscalls_info); |
| 148 | } |
| 149 | |
| 150 | static struct cleanup * |
| 151 | make_cleanup_free_syscalls_info (struct syscalls_info *syscalls_info) |
| 152 | { |
| 153 | return make_cleanup (free_syscalls_info, syscalls_info); |
| 154 | } |
| 155 | |
| 156 | static void |
| 157 | syscall_create_syscall_desc (struct syscalls_info *syscalls_info, |
| 158 | const char *name, int number) |
| 159 | { |
| 160 | struct syscall_desc *sysdesc = XCNEW (struct syscall_desc); |
| 161 | |
| 162 | sysdesc->name = xstrdup (name); |
| 163 | sysdesc->number = number; |
| 164 | |
| 165 | VEC_safe_push (syscall_desc_p, syscalls_info->syscalls, sysdesc); |
| 166 | } |
| 167 | |
| 168 | /* Handle the start of a <syscall> element. */ |
| 169 | static void |
| 170 | syscall_start_syscall (struct gdb_xml_parser *parser, |
| 171 | const struct gdb_xml_element *element, |
| 172 | void *user_data, VEC(gdb_xml_value_s) *attributes) |
| 173 | { |
| 174 | struct syscall_parsing_data *data = user_data; |
| 175 | struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes); |
| 176 | int len, i; |
| 177 | /* syscall info. */ |
| 178 | char *name = NULL; |
| 179 | int number = 0; |
| 180 | |
| 181 | len = VEC_length (gdb_xml_value_s, attributes); |
| 182 | |
| 183 | for (i = 0; i < len; i++) |
| 184 | { |
| 185 | if (strcmp (attrs[i].name, "name") == 0) |
| 186 | name = attrs[i].value; |
| 187 | else if (strcmp (attrs[i].name, "number") == 0) |
| 188 | number = * (ULONGEST *) attrs[i].value; |
| 189 | else |
| 190 | internal_error (__FILE__, __LINE__, |
| 191 | _("Unknown attribute name '%s'."), attrs[i].name); |
| 192 | } |
| 193 | |
| 194 | gdb_assert (name); |
| 195 | syscall_create_syscall_desc (data->syscalls_info, name, number); |
| 196 | } |
| 197 | |
| 198 | |
| 199 | /* The elements and attributes of an XML syscall document. */ |
| 200 | static const struct gdb_xml_attribute syscall_attr[] = { |
| 201 | { "number", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL }, |
| 202 | { "name", GDB_XML_AF_NONE, NULL, NULL }, |
| 203 | { NULL, GDB_XML_AF_NONE, NULL, NULL } |
| 204 | }; |
| 205 | |
| 206 | static const struct gdb_xml_element syscalls_info_children[] = { |
| 207 | { "syscall", syscall_attr, NULL, |
| 208 | GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE, |
| 209 | syscall_start_syscall, NULL }, |
| 210 | { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL } |
| 211 | }; |
| 212 | |
| 213 | static const struct gdb_xml_element syselements[] = { |
| 214 | { "syscalls_info", NULL, syscalls_info_children, |
| 215 | GDB_XML_EF_NONE, NULL, NULL }, |
| 216 | { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL } |
| 217 | }; |
| 218 | |
| 219 | static struct syscalls_info * |
| 220 | syscall_parse_xml (const char *document, xml_fetch_another fetcher, |
| 221 | void *fetcher_baton) |
| 222 | { |
| 223 | struct cleanup *result_cleanup; |
| 224 | struct syscall_parsing_data data; |
| 225 | |
| 226 | data.syscalls_info = allocate_syscalls_info (); |
| 227 | result_cleanup = make_cleanup_free_syscalls_info (data.syscalls_info); |
| 228 | |
| 229 | if (gdb_xml_parse_quick (_("syscalls info"), NULL, |
| 230 | syselements, document, &data) == 0) |
| 231 | { |
| 232 | /* Parsed successfully. */ |
| 233 | discard_cleanups (result_cleanup); |
| 234 | return data.syscalls_info; |
| 235 | } |
| 236 | else |
| 237 | { |
| 238 | warning (_("Could not load XML syscalls info; ignoring")); |
| 239 | do_cleanups (result_cleanup); |
| 240 | return NULL; |
| 241 | } |
| 242 | } |
| 243 | |
| 244 | /* Function responsible for initializing the information |
| 245 | about the syscalls. It reads the XML file and fills the |
| 246 | struct syscalls_info with the values. |
| 247 | |
| 248 | Returns the struct syscalls_info if the file is valid, NULL otherwise. */ |
| 249 | static struct syscalls_info * |
| 250 | xml_init_syscalls_info (const char *filename) |
| 251 | { |
| 252 | char *full_file; |
| 253 | char *dirname; |
| 254 | struct syscalls_info *syscalls_info; |
| 255 | struct cleanup *back_to; |
| 256 | |
| 257 | full_file = xml_fetch_content_from_file (filename, gdb_datadir); |
| 258 | if (full_file == NULL) |
| 259 | return NULL; |
| 260 | |
| 261 | back_to = make_cleanup (xfree, full_file); |
| 262 | |
| 263 | dirname = ldirname (filename); |
| 264 | if (dirname != NULL) |
| 265 | make_cleanup (xfree, dirname); |
| 266 | |
| 267 | syscalls_info = syscall_parse_xml (full_file, |
| 268 | xml_fetch_content_from_file, dirname); |
| 269 | do_cleanups (back_to); |
| 270 | |
| 271 | return syscalls_info; |
| 272 | } |
| 273 | |
| 274 | /* Initializes the syscalls_info structure according to the |
| 275 | architecture. */ |
| 276 | static void |
| 277 | init_syscalls_info (struct gdbarch *gdbarch) |
| 278 | { |
| 279 | struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch); |
| 280 | const char *xml_syscall_file = gdbarch_xml_syscall_file (gdbarch); |
| 281 | |
| 282 | /* Should we re-read the XML info for this target? */ |
| 283 | if (syscalls_info != NULL && syscalls_info->my_gdb_datadir != NULL |
| 284 | && filename_cmp (syscalls_info->my_gdb_datadir, gdb_datadir) != 0) |
| 285 | { |
| 286 | /* The data-directory changed from the last time we used it. |
| 287 | It means that we have to re-read the XML info. */ |
| 288 | free_syscalls_info (syscalls_info); |
| 289 | syscalls_info = NULL; |
| 290 | set_gdbarch_syscalls_info (gdbarch, NULL); |
| 291 | } |
| 292 | |
| 293 | /* Did we succeed at initializing this? */ |
| 294 | if (syscalls_info != NULL) |
| 295 | return; |
| 296 | |
| 297 | syscalls_info = xml_init_syscalls_info (xml_syscall_file); |
| 298 | |
| 299 | /* If there was some error reading the XML file, we initialize |
| 300 | gdbarch->syscalls_info anyway, in order to store information |
| 301 | about our attempt. */ |
| 302 | if (syscalls_info == NULL) |
| 303 | syscalls_info = allocate_syscalls_info (); |
| 304 | |
| 305 | if (syscalls_info->syscalls == NULL) |
| 306 | { |
| 307 | if (xml_syscall_file != NULL) |
| 308 | warning (_("Could not load the syscall XML file `%s/%s'."), |
| 309 | gdb_datadir, xml_syscall_file); |
| 310 | else |
| 311 | warning (_("There is no XML file to open.")); |
| 312 | |
| 313 | warning (_("GDB will not be able to display " |
| 314 | "syscall names nor to verify if\n" |
| 315 | "any provided syscall numbers are valid.")); |
| 316 | } |
| 317 | |
| 318 | /* Saving the data-directory used to read this XML info. */ |
| 319 | syscalls_info->my_gdb_datadir = xstrdup (gdb_datadir); |
| 320 | |
| 321 | set_gdbarch_syscalls_info (gdbarch, syscalls_info); |
| 322 | } |
| 323 | |
| 324 | static int |
| 325 | xml_get_syscall_number (struct gdbarch *gdbarch, |
| 326 | const char *syscall_name) |
| 327 | { |
| 328 | struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch); |
| 329 | struct syscall_desc *sysdesc; |
| 330 | int i; |
| 331 | |
| 332 | if (syscalls_info == NULL |
| 333 | || syscall_name == NULL) |
| 334 | return UNKNOWN_SYSCALL; |
| 335 | |
| 336 | for (i = 0; |
| 337 | VEC_iterate(syscall_desc_p, syscalls_info->syscalls, i, sysdesc); |
| 338 | i++) |
| 339 | if (strcmp (sysdesc->name, syscall_name) == 0) |
| 340 | return sysdesc->number; |
| 341 | |
| 342 | return UNKNOWN_SYSCALL; |
| 343 | } |
| 344 | |
| 345 | static const char * |
| 346 | xml_get_syscall_name (struct gdbarch *gdbarch, |
| 347 | int syscall_number) |
| 348 | { |
| 349 | struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch); |
| 350 | struct syscall_desc *sysdesc; |
| 351 | int i; |
| 352 | |
| 353 | if (syscalls_info == NULL |
| 354 | || syscall_number < 0) |
| 355 | return NULL; |
| 356 | |
| 357 | for (i = 0; |
| 358 | VEC_iterate(syscall_desc_p, syscalls_info->syscalls, i, sysdesc); |
| 359 | i++) |
| 360 | if (sysdesc->number == syscall_number) |
| 361 | return sysdesc->name; |
| 362 | |
| 363 | return NULL; |
| 364 | } |
| 365 | |
| 366 | static const char ** |
| 367 | xml_list_of_syscalls (struct gdbarch *gdbarch) |
| 368 | { |
| 369 | struct syscalls_info *syscalls_info = gdbarch_syscalls_info (gdbarch); |
| 370 | struct syscall_desc *sysdesc; |
| 371 | const char **names = NULL; |
| 372 | int nsyscalls; |
| 373 | int i; |
| 374 | |
| 375 | if (syscalls_info == NULL) |
| 376 | return NULL; |
| 377 | |
| 378 | nsyscalls = VEC_length (syscall_desc_p, syscalls_info->syscalls); |
| 379 | names = xmalloc ((nsyscalls + 1) * sizeof (char *)); |
| 380 | |
| 381 | for (i = 0; |
| 382 | VEC_iterate (syscall_desc_p, syscalls_info->syscalls, i, sysdesc); |
| 383 | i++) |
| 384 | names[i] = sysdesc->name; |
| 385 | |
| 386 | names[i] = NULL; |
| 387 | |
| 388 | return names; |
| 389 | } |
| 390 | |
| 391 | void |
| 392 | set_xml_syscall_file_name (struct gdbarch *gdbarch, const char *name) |
| 393 | { |
| 394 | set_gdbarch_xml_syscall_file (gdbarch, name); |
| 395 | } |
| 396 | |
| 397 | void |
| 398 | get_syscall_by_number (struct gdbarch *gdbarch, |
| 399 | int syscall_number, struct syscall *s) |
| 400 | { |
| 401 | init_syscalls_info (gdbarch); |
| 402 | |
| 403 | s->number = syscall_number; |
| 404 | s->name = xml_get_syscall_name (gdbarch, syscall_number); |
| 405 | } |
| 406 | |
| 407 | void |
| 408 | get_syscall_by_name (struct gdbarch *gdbarch, |
| 409 | const char *syscall_name, struct syscall *s) |
| 410 | { |
| 411 | init_syscalls_info (gdbarch); |
| 412 | |
| 413 | s->number = xml_get_syscall_number (gdbarch, syscall_name); |
| 414 | s->name = syscall_name; |
| 415 | } |
| 416 | |
| 417 | const char ** |
| 418 | get_syscall_names (struct gdbarch *gdbarch) |
| 419 | { |
| 420 | init_syscalls_info (gdbarch); |
| 421 | |
| 422 | return xml_list_of_syscalls (gdbarch); |
| 423 | } |
| 424 | |
| 425 | #endif /* ! HAVE_LIBEXPAT */ |